JPS63145405A - Centrifugal spinning frame - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to spinning materials forming yarns, in particular polyester,
A centrifugal spinning machine for spinning polymers such as polyamides and polyolefins, which is equipped with a pump that supplies the spinning material in liquid form under pressure to the central inlet of the centrifugal spinning machine. Concerning things of the form .

PRIOR ART A centrifugal spinning machine of the above type is disclosed in European Patent Application No. 16.
It is known from US Pat. No. 8,817. In this centrifugal spinning machine, the spinning material is pumped as a spinnable liquid to the central inlet of a spinning pump by an extruder located outside the spinning tube. This measure is intended to increase the spinning pressure beyond what can be achieved by total centrifugal acceleration. A disadvantage of this known centrifugal spinning machine is that it requires a dynamic seal between the feed conduit and the rotating inlet passage of the centrifugal spinning machine, which seal is exposed to significant heat in addition to dynamic loads. They must also withstand heavy loads and therefore lose their sealing properties in the long run. Sealing with a sealing gas is not convenient, since this would require control of the liquid level in the sealing space occupied by the sealing gas.

Problems to be Solved by the Invention The object of the present invention is to find a centrifugal spinning machine in which the spinning solution is supplied under pressure and in which seals are not required.

Means for Solving the Problems The solution of the invention is to provide a centrifugal spinning machine of the type mentioned at the outset, in which the pump is arranged in the central inlet of the centrifugal spinning machine. In addition, the rotating member of the pump is ``rotatably connected to the central inlet of the centrifugal spinning machine.

Effects of the Invention The advantage of the centrifugal spinning machine according to the invention is, inter alia, that because no seals are used, the inlet pressure of the centrifugal spinning machine can be selected to be very high.

As pumps for discharging the spinning solution and generating pressure, in principle all pumps are conceivable which consist of a pair of rotating and stationary parts (for example, a housing and a gear in the case of a gear pump). A special feature according to the invention is that a reversal of the normal pairs is performed. According to the invention, the normally stationary elements thus rotate together with the central inlet of the centrifugal spinning machine, and the normally rotating elements are arranged stationary according to the invention. If the bo/zo is constructed as an internal gear pump, the toothed rim is fixedly connected to the inlet of the centrifugal spinning machine, and the pinion is freely rotatably supported.

Implementation mode In particular, extruders are used as pumps according to the invention.

The advantage of the extruder is that it consists of a coaxial pair of screw and barrel and can therefore be integrated into the central inlet of a centrifugal spinning machine with a simple mechanical construction. A further advantage of the extruder is that it does not require a pressure-loaded seal on the inlet side.

In pumps, and in particular in extruders, according to the invention, since the barrel rotates, it is advantageously proposed to feed the spinning material in liquid form or in the still solid form of granules or granules into the stationary screw; In that case, the screw has an axial feed channel with a radial outflow channel opening into the screw groove.

Another method of supplying the spinning solution in the form of solids, powders, granules, or in liquid form is such that the extruder barrel, i.e. the central inlet channel of the centrifugal spinning machine, is configured with a lightly conical shape in the end region. In fact, this results in a hopper-like feed pocket.

Another advantage of extruders is that they can be used not only for pumping and thus generating pressure, but also for melting spinning materials, such as polymers forming yarns. The metering device for feeding the spinning material into the extruder is therefore designed as a liquid pump or as a feed device for powder or granules. In both cases, the spinning material must be fed in metered amounts. If only the spinning pressure caused by the centrifugal acceleration acts on the liquid spinning material in the centrifugal spinning machine, then even if the metering varies, the amount will be adjusted such that at least the minimum amount is extruded and spun. There must be.

An advantage of the present invention and the use of an extruder is that the centrifugal spinner operates in a self-regulated manner in maintaining this condition. That is, if the amount of material to be spun (spinning rate) is greater than the amount of material fed by the extruder, a pressure break and thus a reduction in the spinning rate takes place in the centrifugal spinning machine. If the amount of yarn to be spun is smaller than the amount fed to the extruder, a pressure buildup takes place in the centrifugal spinning machine, with the result that the amount to be spun is increased. The metering device must be adjusted in such a way that at least the amount of spinning material to be spun under the pressure generated by the centrifugal acceleration is supplied. The maximum amount of spinning material supplied by the metering device must not be greater than the amount of yarn spun at the maximum possible pressure generated by the extruder and centrifugal acceleration.

As already mentioned, the spinning material can be supplied as powder or granules. In this case, it is advantageous if the extruder is constructed in such a way that the spinning material is melted within the extruder. The internal heat generated in the extruder due to the high rotational speed of the barrel relative to the screw will then generally be sufficient for melting. If this is not sufficient, the invention proposes contactless heating (for example by radiation or induction).

If the spinning material is fed in liquid form, the feeding can take place using a metering pump, and the spinning material is then first melted, for example in an extruder.

However, it is also possible to arrange a melt extruder immediately before the extruder assigned to the centrifugal spinning machine. There is a risk of gas evolution due to process operation and type of spun material. For this purpose, it is further proposed to carry out degassing in the inlet of the extruder arranged in the centrifugal spinning machine. For this purpose, vent holes can be provided in the stationary screw.

If the screw has a central inlet channel for supplying the melt, the degassing and vacuum connection is located parallel to the central inlet channel and has a radial outflow channel of the central channel. The screw groove is also open in the area of the open screw groove.

Embodiment FIG. 1 shows a sectional view of a centrifugal spinning machine 1. The centrifuge comprises a centrifugal wheel 2 and a central centrifuge inlet 3 fixedly connected thereto. The centrifugal wheel 2 has a disc-shaped radial chamber 4 or a plurality of radial passages. The radial chambers 4 extend from the central inlet 3 and communicate with the spinning holes 5 on the circumference of the centrifugal wheel 2 . central entrance 3
is configured as an extruder barrel.

The extruder barrel is rotatably supported in a bearing member 6. The extruder barrel 3 is rotated by a drive motor 8 via a drive wheel 7 and a drive belt 9 at a high rotational speed, for example 500 r.
It is driven by p and m. The extruder barrel 3 is heated in a partial section by means of a heating jacket 15 . The heating jacket 15 includes a plurality of electrical heating rods or heating tubes. The heat transfer is preferably carried out contactlessly by radiation, the heating jacket 15 being stationary and forming a narrow gap between it and the extruder barrel 3.

The extruder barrel 3 has a conical configuration in the inlet region of the free end, so that the extruder barrel has a feed end 10t-
It consists of However, the degree of conicity must be low, since otherwise there is a risk that the supplied granules will fly out due to centrifugal force.

Furthermore, the extruder barrel has an axial groove on the inlet side leading to the feed end 10.

The extrusion screw 11 is seated fixedly in a holding element 12 and immovably in the extruder barrel 3. The extrusion screw reaches close to the plane of the radial chamber 4 in this embodiment. For the rest, it is a normal extruder structure, and its design depends on the material to be spun (spinning material) and other operating conditions,
The example depends in particular on the rotational speed of the centrifugal wheel. If the rotational speed of the centrifugal wheel 2 leads to unacceptable shear rates and shear forces in the material to be spun, the screw is rotatably supported and the extruder barrel 3 is moved by means of an additional drive motor.
can be driven in the direction of rotation, so that the relative speed between the extrusion screw 11 and the extruder barrel 3 is reduced.

A suitable drive 26 is shown in broken lines together with a screw bearing 27.

The spinning material is supplied by the metering device 13 in the form of granules. The metering device consists of a feed hopper and a conveyor belt. It is ensured that the quantity supplied per unit of time does not exceed or fall below a certain limit value that depends on the rotational speed of the centrifugal wheel 2. Exceeding the limit value is harmless in itself and merely results in an overflow from the supply end 10. However, it must not fall below the lower limit. The lower limit value is, given the operating conditions (especially temperature, viscosity),
It is the amount of spinnable material per unit of time (spun rate) as spun at a given rotational speed and pressure generated solely by centrifugal acceleration. If the metered amount of spinning material falls below this limit value, the centrifuge idles. In other cases, a spontaneous adjustment takes place with both limit values open, since an equilibrium exists between the supplied quantity, the pressure exerted on the spinning material by the extruder and the centrifugal acceleration, and the spinning quantity. This is because you can get it.

The centrifugal spinning machine 1 according to FIG. 2 likewise has a centrifugal wheel 2 and a central inlet 3, which is designed as an extrusion-like barrel. The extruder barrel 3 is rotatably supported in a bearing member 6 and is rotationally driven by a drive belt 9, a drive wheel 7 and a drive motor 8. The spinning hole is designated by 5. You can see the thread coming out from here.

As in the embodiment according to FIG. 1, a radial channel is provided inside the spinning volume, which communicates the central inlet 3 with the spinning hole 5. In the embodiment according to FIG. 2 the extrusion screw 11 has a lower cylindrical part 11
(which extends approximately into the centrifugal wheel 2) as well as a supply area 16 and a holding part 17. The holding part 17 is secured in the holding part 12 in a relatively rotationally fixed manner and in the axial direction. A supply area follows the holding member portion.

The feed area 16 is of conical configuration corresponding to the feed end 10 of the extruder barrel. The holding member part 17 and the supply area 16 are penetrated by a central passage 1B (supply passage). The feed passage 18 opens into a radial outlet 20 at the conical feed end 10 of the extruder barrel. The radial outlet is shown as a helical notch in the screw surface. The helical notch is the extrusion screw 1
It opens into one or more screw grooves. A supply pipe 19 communicates with the supply channel 18 and is connected to a metering device 13, in this embodiment a gear metering pump. Via the gear metering pump 13 and the feed line 19, a precisely metered amount is fed into the feed channel 18 and into the helical recess 20 of the extruder.

The metering pump 13 is fed by a bath melt extruder 24 . The melt extruder 24 is supplied with a metered amount of spinning material as powder or granules.

As indicated by the dashed line 24, the spinning material melted by the melt extruder 24 can also be fed directly into the feed line 19 of the centrifugal spinning machine.

Melting of the spun material may cause monomers or other constituent materials to vaporize or be liberated as a gas. For this purpose, the holding part 17 of the extrusion screw 11 is equipped with a vacuum connection 22, which serves as a gas venting channel. The degassing channel is located parallel to the supply channel 18 and opens into a helical cutout 20. The supplied liquid spinning material flows out in this recess radially outwards into the screw groove. A low pressure pump can be connected to the gas vent passage 22.

This facilitates degassing.

A sealing member is indicated by the reference numeral 21.

This sealing member seals the supply pipe 19 within the supply passage of the screw. It can be recognized that this sealing element then only has to withstand very small melt pressures in the feed area of the extruder. The same applies to the sealing element 23, which seals against the retaining element part 1Yt of the screw - the feed end of the extruder barrel 3. Between the sealing elements 21 and 23 is located the area of the melt channel, in which the melt is exposed to vacuum.

In operation: The metering device 13 supplies the spinning material, ie the material forming the thread, in the form of granules or powder (FIG. 1) or in the form of a melt (FIG. 2) to the centrifugal spinning machine. The material may be, for example, polyzolopyrene, polyamide, polyester. The spinning material enters the extruder barrel 3, which rotates at high rotational speed. In the embodiment according to FIG. 2, degassing takes place in the inlet of the extruder barrel 3. In the embodiment according to FIG. 1, the spinning material is melted by a relative movement between a stationary (or slowly co-rotating) screw and a rotating extruder barrel, and in the other case by a centrifugal wheel 2 under high pressure. Send it inside.

The spinning material is diverted in a centrifugal wheel and sent outward into a radial passage. The spun material is under pressure in the radial passages, on the one hand, generated by the extruder, and on the other hand, under the pressure generated by the centrifugal force.

The use of an extruder (the extruder being located in the central inlet of the centrifugal spinning machine) is advantageous because such an extruder does not require seals that are exposed to high pressure. The extruder can generate pressures that correspond to those commonly used during spinning. Therefore, even highly viscous melts can be spun into fine fineness without unacceptably increasing the speed at which the yarn is drawn from the nozzle.

On the other hand, the rotation speed of the centrifugal spinning machine can be adjusted and optimized independently of the pressure required for spinning.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an embodiment of a centrifugal spinning machine according to the present invention in which the material forming the thread is supplied in the form of granules, and FIG. 2 shows the material forming the thread being supplied in the form of a melt. FIG. 2 is a partially cutaway view of an embodiment of the type supplied in FIG. DESCRIPTION OF SYMBOLS 1... Centrifugal spinning machine, 2... Centrifugal wheel, 3... Extruder barrel, 4... Radial direction chamber, 5... Spinning hole, 6...
... Supporting member, 7... Drive base, 8... Drive motor,
9... Drive belt, 10... Supply end, 11...
Extrusion screw, 12... Holding member, 13... Measuring device, 14... Granules, 15... Heating jacket, 1
6... Supply area, 17... Holding member portion, 18...
- Supply passage, 19... Supply pipe, 20... Notch, 2
1.23... Seal member, 22... Gas vent passage,
24... Melt extruder, 25... Conduit, 26... Drive device, 27... Screw support member.

Claims (1)

[Claims] 1. A centrifugal spinning machine for spinning yarn from a spinning material, which is equipped with a pump, and the pump moves the spinning material in liquid form to the center of the centrifugal spinning machine. In those types in which the inlet is supplied under pressure, the pump is located in the central inlet of the centrifugal spinning machine;
A centrifugal spinning machine, characterized in that the rotating member of the pump is connected to a central inlet of the centrifugal spinning machine in a relatively unrotatable manner. 2. The pump is an extruder, the extruder is arranged coaxially with respect to the centrifugal spinning machine, the extrusion screw is supported stationary, and the central inlet of the centrifugal spinning machine rotates. 2. A centrifugal spinning machine as claimed in claim 1, which surrounds the extrusion screw as a barrel. 3. The centrifugal spinning machine according to claim 1, wherein a metering device is arranged in front of the pump to meter the liquid spinning material. 4. The centrifuge according to claim 2, wherein a metering device for granules or powder is arranged in front of the extruder, and the extruder is also used for melting the granules or powder. Type spinning machine. 5. Centrifugal according to claim 4, characterized in that the extruder barrel is surrounded by a stationary heating jacket, which heating jacket is adapted to transmit the necessary heating energy in a contactless manner. Type spinning machine. 6. The centrifugal spinning machine according to claim 3, wherein another melt extruder is arranged in front of the extruder. 7. The centrifugal spinning machine according to claim 6, wherein a vacuum is provided in the inlet of the centrifugal spinning machine for degassing the liquid spinning material. 8. The stationary extrusion screw is provided with a central feed hole having a radial outlet opening into the screw groove;
A centrifugal spinning machine according to any one of claims 1 to 7. 9. The centrifugal spinning machine according to claim 8, wherein a vacuum is provided in the region of the screw groove in which one or more outlet channels are opened.